1 /*
2 * Copyright (c) 1982, 1986, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * From: @(#)if_loop.c 8.1 (Berkeley) 6/10/93
30 * $FreeBSD: src/sys/net/if_disc.c,v 1.26.2.2 2001/12/20 10:30:16 ru Exp $
31 */
32
33 /*
34 * Discard interface driver for protocol testing and timing.
35 * (Based on the loopback.)
36 */
37
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/kernel.h>
41 #include <sys/module.h>
42 #include <sys/mbuf.h>
43 #include <sys/socket.h>
44 #include <sys/sockio.h>
45
46 #include <net/if.h>
47 #include <net/if_types.h>
48 #include <net/ifq_var.h>
49 #include <net/route.h>
50 #include <net/bpf.h>
51
52 #include "opt_inet.h"
53 #include "opt_inet6.h"
54
55 #ifdef TINY_DSMTU
56 #define DSMTU (1024+512)
57 #else
58 #define DSMTU 65532
59 #endif
60
61 static void discattach (void);
62
63 static struct ifnet discif;
64 static int discoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
65 struct rtentry *);
66 static void discrtrequest(int cmd, struct rtentry *rt);
67 static int discioctl(struct ifnet *, u_long, caddr_t, struct ucred *);
68
69 /* ARGSUSED */
70 static void
discattach(void)71 discattach(void)
72 {
73 struct ifnet *ifp = &discif;
74
75 if_initname(ifp, "ds", IF_DUNIT_NONE);
76 ifp->if_mtu = DSMTU;
77 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
78 ifp->if_ioctl = discioctl;
79 ifp->if_output = discoutput;
80 ifp->if_type = IFT_LOOP;
81 ifp->if_hdrlen = 0;
82 ifp->if_addrlen = 0;
83 ifq_set_maxlen(&ifp->if_snd, 20);
84 if_attach(ifp, NULL);
85 bpfattach(ifp, DLT_NULL, sizeof(uint32_t));
86 }
87
88 static int
disc_modevent(module_t mod,int type,void * data)89 disc_modevent(module_t mod, int type, void *data)
90 {
91 switch (type) {
92 case MOD_LOAD:
93 discattach();
94 break;
95 case MOD_UNLOAD:
96 kprintf("if_disc module unload - not possible for this module type\n");
97 return EINVAL;
98 }
99 return 0;
100 }
101
102 static moduledata_t disc_mod = {
103 "if_disc",
104 disc_modevent,
105 NULL
106 };
107
108 DECLARE_MODULE(if_disc, disc_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
109
110 static int
discoutput(struct ifnet * ifp,struct mbuf * m,struct sockaddr * dst,struct rtentry * rt)111 discoutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
112 struct rtentry *rt)
113 {
114 if ((m->m_flags & M_PKTHDR) == 0)
115 panic("discoutput no HDR");
116 /* BPF write needs to be handled specially */
117 if (dst->sa_family == AF_UNSPEC) {
118 dst->sa_family = *(mtod(m, int *));
119 m->m_len -= sizeof(int);
120 m->m_pkthdr.len -= sizeof(int);
121 m->m_data += sizeof(int);
122 }
123
124 if (discif.if_bpf) {
125 bpf_gettoken();
126 if (discif.if_bpf) {
127 /*
128 * We need to prepend the address family as
129 * a four byte field.
130 */
131 uint32_t af = dst->sa_family;
132
133 bpf_ptap(discif.if_bpf, m, &af, sizeof(af));
134 }
135 bpf_reltoken();
136 }
137 m->m_pkthdr.rcvif = ifp;
138
139 IFNET_STAT_INC(ifp, opackets, 1);
140 IFNET_STAT_INC(ifp, obytes, m->m_pkthdr.len);
141
142 m_freem(m);
143 return 0;
144 }
145
146 /* ARGSUSED */
147 static void
discrtrequest(int cmd,struct rtentry * rt)148 discrtrequest(int cmd, struct rtentry *rt)
149 {
150 if (rt)
151 rt->rt_rmx.rmx_mtu = DSMTU;
152 }
153
154 /*
155 * Process an ioctl request.
156 */
157 /* ARGSUSED */
158 static int
discioctl(struct ifnet * ifp,u_long cmd,caddr_t data,struct ucred * cr)159 discioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr)
160 {
161 struct ifaddr *ifa;
162 struct ifreq *ifr = (struct ifreq *)data;
163 int error = 0;
164
165 switch (cmd) {
166
167 case SIOCSIFADDR:
168 ifp->if_flags |= IFF_UP;
169 ifa = (struct ifaddr *)data;
170 if (ifa != NULL)
171 ifa->ifa_rtrequest = discrtrequest;
172 /*
173 * Everything else is done at a higher level.
174 */
175 break;
176
177 case SIOCADDMULTI:
178 case SIOCDELMULTI:
179 if (ifr == NULL) {
180 error = EAFNOSUPPORT; /* XXX */
181 break;
182 }
183 switch (ifr->ifr_addr.sa_family) {
184
185 #ifdef INET
186 case AF_INET:
187 break;
188 #endif
189 #ifdef INET6
190 case AF_INET6:
191 break;
192 #endif
193
194 default:
195 error = EAFNOSUPPORT;
196 break;
197 }
198 break;
199
200 case SIOCSIFMTU:
201 ifp->if_mtu = ifr->ifr_mtu;
202 break;
203
204 default:
205 error = EINVAL;
206 }
207 return (error);
208 }
209